The present disclosure relates to subject matter contained in Japanese Patent Application No. 11-1738 (filed on Jan. 7, 1999) and Japanese Patent Application No. 11-1739 (filed on Jan. 7, 1999), which are expressly incorporated herein by reference in their entireties.
1. Field of the Invention
The present invention relates to a high-frequency instrument that is removably inserted into an instrument-inserting channel of an endoscope and used to carry out a treatment by passing a high-frequency electric current therethrough.
2. Description of the Prior Art
In general, a high-frequency instrument for an endoscope has a high-frequency electrode secured to the distal end of a sheath that is removably inserted into an instrument-inserting channel of an endoscope. A operating part is connected to the proximal end of the sheath, and an electrically conducting member that is electrically connected to the high-frequency electrode is disposed in the operating part.
A high-frequency treatment using an endoscope is performed as follows. A patient plate is set in close contact with the patient""s body, and the high-frequency electrode, which is provided at the distal end of the sheath, is touched to the affected part to pass a high-frequency electric current between the two electrodes.
The electric current flows through a circuit formed between the patient""s body and a high-frequency power supply. Therefore, the doctor is not included in the high-frequency circuit if touching the conducting path of the instrument. As in the case of a bird perching on an electric line without getting an electric shock, the doctor can touch the conducting path without causing an accident.
However, if the doctor touches the conducting path of the instrument while being in contact with the patient""s body or electrically connected to the patient plate through another conducting path, a high-frequency circuit is formed through the doctor""s body. This may cause the part of the doctor""s body touching the conducting path to be burned.
An object of the present invention is to provide a high-frequency instrument for an endoscope that allows the doctor to perform an endoscopic high-frequency treatment with improved safety, without the danger of causing an accident resulting in a burn.
Other objects and advantages of the present invention will become apparent from the following detailed description of illustrated embodiments of the invention.
According to the present invention, there is provided a high-frequency instrument for an endoscope including an electrically insulating sheath having a high-frequency electrode provided at the distal end thereof. A operating part is connected to the proximal end of the sheath. The operating part includes an electrically conducting member electrically connected to the high-frequency electrode. The operating part further includes a connecting terminal for connection to a high-frequency power supply. An electrically insulating member covers the whole outer surface of the electrically conducting member.
In addition, there is provided a high-frequency instrument for an endoscope including an electrically insulating sheath having an electrically conductive rod inserted therein. The rod projects from the proximal end of the sheath and is electrically connected to a high-frequency electrode provided at the distal end of the sheath. A operating part is detachably connected to the proximal end of the sheath. The operating part includes an operating member disengageably engaged with the rod. An electrically insulating member covers the whole outer surface of the rod except a portion thereof that is engageable with the operating member.